After several horrific wrong-way crashes in Florida, including one in 2013 in which two 21-year-old best friends from Coral Springs were killed, traffic officials began installing warning systems at highway entrance ramps.

There are now flashing signs and cameras at many dangerous interchanges, including some on the Sawgrass Expressway in Broward County.

But there are no such warning devices at all on Interstate 95 in Volusia County where a head-on, wrong-way crash early Sunday took the life of another 21-year-old woman from Broward County.

Jennifer Starr Otto, a college student who was returning home to Pompano Beach from a visit to South Carolina, was a passenger in a 2013 Toyota Prius that was hit by a pickup truck traveling north in the southbound lanes of I-95 near Ormond Beach early Sunday, authorities said.

Injured was the driver of the Prius, Maria Stengel, 29, a Hillsboro Beach police officer and a Boca Raton resident. Stengel remained in serious condition Monday in Halifax Medical Center in Daytona Beach.

Both women were wearing seat belts, officials said.

The driver of the 2007 Ford pickup truck that hit the Prius was identified as Alex Edward Jamison, 28, of Simpsonville, S.C. The truck overturned and caught fire, investigators said, but Jamison was able to get out of the vehicle on his own.

Jamison, also wearing a seat belt, sustained minor injuries.

FHP Sgt. Kim Montes said investigators have not determined how Jamison ended up going up I-95 on the wrong side of the road. “We are still trying to determine if he made a U-turn or got on the wrong way [at a ramp],” she said.

Investigators obtained a warrant to draw blood from Jamison on “suspicion of possible impairment,” said Montes. “All the witnesses said he was going the wrong way.”

Criminal charges are pending toxicology results, investigators said.

Although fatal wrong-way crashes are relatively rare when compared to all traffic accidents, investigators say, they are particularly violent.

“The Prius looked like it was folded into a hunk of metal,” said Montes. “It is surprising the driver came out alive.”

These head-on crashes usually occur at night or in the early morning, and often involve someone impaired by alcohol or drugs, according to a Florida Department of Transportation study published in April 2015.

That study looked at 280 wrong-way crashes that occurred on Florida expressways between 2009 and 2014 that resulted in more than 400 injuries and 75 deaths.

Alcohol and/or drugs were involved in 45 percent of wrong-way crashes, more than 16 times the alcohol and/or drug involvement proportion for freeway/expressway crashes in Florida, the study found.

The majority of wrong-way crashes (71 percent) occurred in dark conditions, compared with 29 percent of general expressway crashes in Florida.

Warning devices — flashing beacons, solar-powered warning signs and vehicle-detection equipment — were installed on 10 ramps on the turnpike's Homestead Extension between Miramar and Doral and on five ramps on the Sawgrass Expressway in Broward.

If a motorist goes the wrong way or enters the roadway using an exit ramp and misses the flashing signs, a camera will send a picture of the vehicle to the FHP's command center and to the Turnpike's traffic management center in Pompano Beach. Traffic managers can then program overhead signs on the highway to alert motorists that a wrong-way driver is in the area.

In its first year, the alert system prevented at least 14 wrong-way wrecks on the Sawgrass Expressway and also a stretch of Florida's Turnpike in Miami-Dade, according to state data released in October 2015.

The 14 vehicles going the wrong way were detected by the devices, which flashed warnings and simultaneously alerted authorities. Because no crash occurred and the vehicles did not show up on other roadside cameras, turnpike officials say the drivers must have turned around on the ramps.

Officials say the driver, Harold Wilson Martinez, 36, of Parkland, ignored the flashing warning signs and headed north on the southbound lanes at the Sample Road exit. Cameras snapped a picture of a vehicle going the wrong way, and a minute later authorities got a 911 call that he hit another vehicle.

But deadly crashes continue to happen.

“We see this as a problem,” said Montes. In Orange County, for example, where several entrance ramps are monitored by wrong-way cameras, “we sometimes get two or three pictures a day of people driving on the wrong side of the highway.”

Not all of those incidents end in crashes, she said. “They either turn around or get on the right side of the road,” Montes said.

For those motorists who do drive often at night, Montes advises to avoid the passing lane, because an unaware wrong-way driver may perceive that as their inside lane.

The crash that claimed Otto’s life occurred at 1:15 a.m.

Fred Otto said his daughter and Stengel had made a visit to Coastal Carolina University in Conway, S.C., where Jennifer had attended school.

She planned to enroll in Broward College this fall and aspired to be a nurse or a veterinarian, Fred Otto said.

“She was kind and caring to everybody, loved to help people out,” said Otto of his daughter.

Jennifer Otto worked as a nanny, looking after children, and also at ice skating rinks in Pompano Beach and Coral Springs, her father said.

Stengel has worked for the Town of Hillsboro Beach for about six years, first as a police dispatcher. After graduating from the police academy, she was sworn in as a police officer in January 2016 and is assigned to road patrol, according to Police Maj. Jay Szesnat.

“This is just shocking,” said Szesnat. “Our hearts go out to all the families involved.”